• The Stability of Belief: How Rational Belief Coheres with Probability, by LeitgebHannes. Oxford: Oxford University Press, 2017. Pp. xiv + 365.
  • In everyday life we either express our beliefs in all-or-nothing terms or we resort to numerical probabilities: I believe it's going to rain or my chance of winning is one in a million. The Stability of Belief develops a theory of rational belief that allows us to reason with all-or-nothing belief and numerical belief simultaneously.
  • This article suggests that scientific philosophy, especially mathematical philosophy, might be one important way of doing philosophy in the future. Along the way, the article distinguishes between different types of scientific philosophy; it mentions some of the scientific methods that can serve philosophers; it aims to undermine some worries about mathematical philosophy; and it tries to make clear why in certain cases the application of mathematical methods is necessary for philosophical progr…Read more
  • Digital Literature Analysis for Empirical Philosophy of Science
    British Journal for the Philosophy of Science (4): 875-898. 2021.
    Empirical philosophers of science aim to base their philosophical theories on observations of scientific practice. But since there is far too much science to observe it all, how can we form and test hypotheses about science that are sufficiently rigorous and broad in scope, while avoiding the pitfalls of bias and subjectivity in our methods? Part of the answer, we claim, lies in the computational tools of the digital humanities, which allow us to analyze large volumes of scientific literature. H…Read more
  • Property Identity and Reification
    Australasian Philosophical Review 4 (4): 367-372. 2020.
    ABSTRACT The target article uses the metaphysics of properties to make its meta-ethical claims. This comment discusses two general points in the metaphysics of properties. The first point has to do with the conditions for property identity. Philosophers who accept the existence of properties have proposed a variety of criteria for their identity. The standard Broome applies is medium coarse. Other standards for property identity could be evaluated for their appropriateness for addressing questio…Read more
  • A Computationally-Discovered Simplification of the Ontological Argument
    Australasian Journal of Philosophy 89 (2): 333-349. 2011.
    The authors investigated the ontological argument computationally. The premises and conclusion of the argument are represented in the syntax understood by the automated reasoning engine PROVER9. Using the logic of definite descriptions, the authors developed a valid representation of the argument that required three non-logical premises. PROVER9, however, discovered a simpler valid argument for God's existence from a single non-logical premise. Reducing the argument to one non-logical premise br…Read more
  • I propose a straightforward reconciliation of Leibniz’s conception of bodies as aggregates of simple substances (i.e., monads) with his doctrine that bodies are the phenomena of perceivers, without in the process saddling him with any equivocations. The reconciliation relies on the familiar idea that in Leibniz’s idiolect, an aggregate of Fs is that which immediately presupposes those Fs, or in other words, has those Fs as immediate requisites. But I take this idea in a new direction. Taking not…Read more
  • Steps Toward a Computational Metaphysics
    Journal of Philosophical Logic 36 (2): 227-247. 2007.
    In this paper, the authors describe their initial investigations in computational metaphysics. Our method is to implement axiomatic metaphysics in an automated reasoning system. In this paper, we describe what we have discovered when the theory of abstract objects is implemented in PROVER9 (a first-order automated reasoning system which is the successor to OTTER). After reviewing the second-order, axiomatic theory of abstract objects, we show (1) how to represent a fragment of that theory in PRO…Read more
  • Program semantics and classical logic
    In CLAUS Report Nr 86, University of the Saarland. pp. 1-27. 1997).
    In the tradition of Denotational Semantics one usually lets program constructs take their denotations in reflexive domains, i.e. in domains where self-application is possible. For the bulk of programming constructs, however, working with reflexive domains is an unnecessary complication. In this paper we shall use the domains of ordinary classical type logic to provide the semantics of a simple programming language containing choice and recursion. We prove that the rule of {\em Scott Induction\/}…Read more
  • A Paradigm for Program Semantics: Power Structures and Duality
    Chris Brink and Ingrid Rewitsky
    Center for the Study of Language and Inf. 2001.
    This book provides a synthesis of four versions of program semantic—srelational semantics, predicate transformer semantics, information systems, and domain theory—showing, through an exhaustive case study analysis, that it is possible to do back-and-forth translation from any of these versions of program semantics into any of the others, and demonstrating that while there are many variations of each, in principle they may be thought of as intertranslatable.
  • Modal science
    Canadian Journal of Philosophy 46 (4-5): 453-492. 2016.
    This paper explains and defends the idea that metaphysical necessity is the strongest kind of objective necessity. Plausible closure conditions on the family of objective modalities are shown to entail that the logic of metaphysical necessity is S5. Evidence is provided that some objective modalities are studied in the natural sciences. In particular, the modal assumptions implicit in physical applications of dynamical systems theory are made explicit by using such systems to define models of a …Read more
  • A Theory of Necessities
    Journal of Philosophical Logic 51 (1): 151-199. 2022.
    We develop a theory of necessity operators within a version of higher-order logic that is neutral about how fine-grained reality is. The theory is axiomatized in terms of the primitive of *being a necessity*, and we show how the central notions in the philosophy of modality can be recovered from it. Various questions are formulated and settled within the framework, including questions about the ordering of necessities under strength, the existence of broadest necessities satisfying various logic…Read more
  • Arithmetic is Determinate
    Journal of Philosophical Logic 51 (1): 127-150. 2021.
    Orthodoxy holds that there is a determinate fact of the matter about every arithmetical claim. Little argument has been supplied in favour of orthodoxy, and work of Field, Warren and Waxman, and others suggests that the presumption in its favour is unjustified. This paper supports orthodoxy by establishing the determinacy of arithmetic in a well-motivated modal plural logic. Recasting this result in higher-order logic reveals that even the nominalist who thinks that there are only finitely many …Read more
  • In recent years what has come to be called the 'New Mechanism' has emerged as a framework for thinking about the philosophical assumptions underlying many areas of science, especially in sciences such as biology, neuroscience, and psychology. This book offers a fresh look at the role of mechanisms, by situating novel analyses of central philosophical issues related to mechanisms within a rich historical perspective of the concept of mechanism as well as detailed case studies of biological mechan…Read more
  • According to a simple Bayesian argument from evil, the evil we observe is less likely given theism than given atheism, and therefore lowers the probability of theism. I consider the most common skeptical theist response to this argument, according to which our cognitive limitations make the probability of evil given theism inscrutable. I argue that if skeptical theists are right about this, then the probability of theism given evil is itself largely inscrutable, and that if this is so, we ought …Read more
  • The existence and fundamentality of spacetime has been questioned in quantum gravity where spacetime is frequently described as emerging from a more fundamental non-spatiotemporal ontology. This is supposed to lead to various philosophical issues such as the problem of empirical coherence. Yet those issues assume beforehand that we actually understand and agree on the nature of spacetime. Reviewing popular conceptions of spacetime, we find that there is substantial disagreement on this matter, a…Read more
  • This book provides an up-to-date overview of the foundations of spacetime physics. It features original essays written by world-class experts in the physics and philosophy of spacetime. The foundational questions regarding the origin and nature of spacetime are branching into new and exciting directions. These questions are not restricted to the quantum gravity program but also arise in the context of a well-established theory like general relativity. Against the background of these quick and di…Read more
  • Aristotle, Logic, and QUARC
    History and Philosophy of Logic 39 (4): 305-340. 2018.
    The goal of this paper is to present a new reconstruction of Aristotle's assertoric logic as he develops it in Prior Analytics, A1-7. This reconstruction will be much closer to Aristotle's original...
  • Evidentialism and belief polarization
    Synthese 198 (8): 7165-7196. 2021.
    Belief polarization occurs when subjects who disagree about some matter of fact are exposed to a mixed body of evidence that bears on that dispute. While we might expect mutual exposure to common evidence to mitigate disagreement, since the evidence available to subjects comes to consist increasingly of items they have in common, this is not what happens. The subjects’ initial disagreement becomes more pronounced because each person increases confidence in her antecedent belief. Kelly aims to id…Read more
  • The rules of thought
    Oxford University Press. 2013.
    Ichikawa and Jarvis offer a new rationalist theory of mental content and defend a traditional epistemology of philosophy. They argue that philosophical inquiry is continuous with non-philosophical inquiry, and can be genuinely a priori, and that intuitions do not play an important role in mental content or the a priori.
  • The Routledge Handbook of Epistemic Contextualism (edited book)
    Jonathan Jenkins Ichikawa
    Routledge. 2017.
    Epistemic contextualism is a recent and hotly debated topic in philosophy. Contextualists argue that the language we use to attribute knowledge can only be properly understood relative to a specified context. How much can our knowledge depend on context? Is there a limit, and if so, where does it lie? What is the relationship between epistemic contextualism and fundamental topics in philosophy such as objectivity, truth, and relativism? The Routledge Handbook of Epistemic Contextualism is an out…Read more
  • Forall x (UBC Edition)
    Creative Commons: Attribution-ShareAlike 3.0. 2020.
    This is an open-access introductory logic textbook, prepared by Jonathan Ichikawa, based on P.D. Magnus's forallx. This (v2.0, July 2020) is intended as a stable, ready-for-teaching edition.
  • Fregean senses, modes of presentation, and concepts
    Philosophical Perspectives 15 335-359. 2001.
    of my axiomatic theory of abstract objects.<sup>1</sup> The theory asserts the ex- istence not only of ordinary properties, relations, and propositions, but also of abstract individuals and abstract properties and relations. The
  • Information without truth
    Metaphilosophy 41 (3): 313-330. 2010.
    Abstract: According to the Veridicality Thesis, information requires truth. On this view, smoke carries information about there being a fire only if there is a fire, the proposition that the earth has two moons carries information about the earth having two moons only if the earth has two moons, and so on. We reject this Veridicality Thesis. We argue that the main notions of information used in cognitive science and computer science allow A to have information about the obtaining of p even when …Read more
  • Quantified Modal Logic and Quine's Critique: Some Further Observations
    Saul A. Kripke
    Noûs 51 (2): 235-237. 2017.
  • The Routledge Handbook of Modality (edited book)
    Otávio Bueno and Scott Shalkowski
    Routledge. 2018.
    Modality - the question of what is possible and what is necessary - is a fundamental area of philosophy and philosophical research. The Routledge Handbook of Modality is an outstanding reference source to the key topics, problems and debates in this exciting subject and is the first collection of its kind. Comprising thirty-five chapters by a team of international contributors the Handbook is divided into seven clear parts: worlds and modality essentialism, ontological dependence, and modality m…Read more
  • This collection highlights the new trend away from rationalism and toward empiricism in the epistemology of modality. Accordingly, the book represents a wide range of positions on the empirical sources of modal knowledge. Readers will find an introduction that surveys the field and provides a brief overview of the work, which progresses from empirically-sensitive rationalist accounts to fully empiricist accounts of modal knowledge. Early chapters focus on challenges to rationalist theories, esse…Read more
  • Leibniz's modal metaphysics
    Stanford Encyclopedia of Philosophy. 2008.
    In the main article on Leibniz, it was claimed that Leibniz's philosophy can be seen as a reaction to the Cartesian theory of corporeal substance and the necessitarianism of Spinoza and Hobbes. This entry will address this second aspect of his philosophy. In the course of his writings, Leibniz developed an approach to questions of modality—necessity, possibility, contingency—that not only served an important function within his general metaphysics, epistemology, and philosophical theology but al…Read more
  • Descartes' modal metaphysics
    Stanford Encyclopedia of Philosophy. 2008.
  • The rationalists
    Oxford University Press. 1988.
    The seventeenth century saw a major revolution in our ways of thinking about such issues as the method appropriate to philosophy and science, the relation between mind and body, the nature of substance, and the place of humanity in nature. While not neglecting the lesser but still influential figures, such as Arnauld and Malebranche, John Cottingham focuses primarily on the three great "rationalists": Descartes, Spinoza, and Leibniz. He examines how they approached central problems of philosophy…Read more